Dump body hoist mechanism



July 1 3, 1937. P. A. BRICK 2,087,138

. DUMP BODY HQIST MECHANISM I 2 Sheets-Sheet 1 Filed May 24, 1955 PERRY /7. BRICK- gwucnkvb PERRY fi. 5mm.

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- P. A. BRICK DUMP BODY HOIST MECHANISM Flled May 24 1935 July 13, 1937.

Patented July 13, 1937 UNITED STATES DUMP BODY HOIST MECHANISM Perry A. Brick, Galion, Ohio, assignor to Perfection Steel Body Company, Galion, Ohio, a

corporation Application May 24, 1935, Serial No. 23,302

3 Claims.

This application is a continuation in part of my co-pending application Serial No. 721,824, filed April 21, 1934, for Hydraulic hoist for dump bodies.

My invention involves certain improvements in hydraulic hoist mechanism of the type which are commonly used today for incorporation in automotive vehicles or trucks for the purpose of lifting dump bodies mounted upon the truck frame.

The special construction of hydraulic hoist employed by me utilizes a cylinder for the reception of the motive fluid, preferably oil, piston means mounted in said cylinder and connected by its piston rod to an operating head exterior to the cylinder, together with linkage connections intermediate said operating head and the body which is to be raised and lowered, whereby the lifting pressure ,derived from the fluid in the cylinder may be transmitted through the links to the said body for elevating the latter. The operating head according to my construction is equippedwith rollers to travel upon tracks or rails mounted on the frame of the vehicle in the back and front movement of the head for the elevating and lowering movements of the body as caused by the link connections therewith.

Involved in my invention is a peculiar arrangement and mounting for the rollers carried by the operating head such that the thrust of the links which converge toward each other at the points of connection with the head will in no way be transmitted to the roller soas to interfere with the freedom of action of the latter in their travel upon the rails or tracks provided therefor. Another feature of my invention resides in the provision of a combinationstop and guide device to cooperate with the operating head which actuates the links by which the body is raised to dumping or tilted position.

Still another feature of my invention resides in the provision in the cylinder of an oil passage associated with the low pressure port of the cylinder. This passage is for facilitating the returnor lowering action of the dump body to its normal loading position, after the piston movement has carried the piston to a position closing this low pressure port against the exhaust fiow of pressure fluid. Said piston movement is caused by the action of the fluid at high pressure against t working side of the piston, during the elevatingmovement of the body to its tilting or dumping position.

' In the accompanying drawings-- Figurel is a top plan view showing the general chassis of a truck equipped with the hydraulic hoist mechanism of the invention, the dump body omitted, but the hydraulic mechanism being shown asconnected with the lifting or elevating 5 links that are to be attached to the dump body.

Figure 2 is a side elevation of substantially all the parts illustrated in Figure 1.

Figure 3 is a fragmentary sectional view of the rear end ofthe cylinder, illustrating more clearly 10 the low pressure port and the fluid passage leading therefrom inthe direction of the rear cylinder head.

Figure 4 is a fragmentary perspective View showing a portion of the chassis of the truck 15 which carries the dump body, the latter partially illustrated in a fragmentary manner, the View bringing out somewhat more fully the mounting of the guide and stop devices cooperating With the piston head to limit its rearward movement and to prevent dumping of the operating head on the piston rod, with its rollers, off of the roller track where it is normally supported, the said stopand guide members also acting to guide the head in its longitudinal actuating movement. 25

Since the invention is applicable to various types of chassis or frame structures of dumping trucks, the frame construction per se is not a material feature of the invention save as it is combined with the parts of the cylinder, operat- 30 ing head, lifting links, and track arrangements that will be more fully set forth shortly. In the drawings the dumping body illustrated is designated A and may be any one of many different types commonly used. It is pivotally mounted by 5 brackets I upon the side members 2 of the main chassis or frame of the vehicle by means of an axis rod 3 or any suitable pivot connections that may be selected or desired. The chassis frame according to this invention may be conventional 40 save and except in respect to the employment of longitudinal rails or track members 4, the said track members being connected at the front of the chassis with a cross member 5 and at the rear portion of the chassis with a cross member 6 located some distance in advance of the axis means 3 previously referred to.

At the front portion of the chassis or frame of the vehicle is disposed the pump 1 which may be of a known type adapted to be operated by suitable shaft means partially shown at 8, the latter to be connected with the power take-off adapted to be attached to the truck transmission means, this feature of construction not, however, being a part of the present invention, as previously indicated. From the pump 1 an intake pipe 9 leads to the front end of the cylinder assembly which includes the cylinder III, said pipe 9 being connected with a coupling supported by a trunnion I I carried by and rigidly fastened tothe head at the high pressure end of the cylinder. The trunnion I I is hollow so that the pipe line 9 may ,conduct the oil therethrough into the high pressure end of the cylinder I0, as will be obvious. However; it is notable that the trunnion II is substantially concentric with the axis of the cylinder I and free to turn in a bearing on the cylinder supporting member I2 which takes the form of an angle plate rigidly mounted upon the front ends of the track members 4 and frame sides 2, the vertical flange of said angle plate having the said bearing formed therein. Thus the high pressure end of the cylinder II] has a one-point suspension or supporting mounting. At the rear end thereof, the cylinder I9 is carried by special separate brackets I3 fastened to the inner sides of the track members 4 at corresponding outer ends and fastened to the rear cylinder head I4 at their corresponding inner ends, as well seen in Figure 2, the parts I2 and I3 affording a three-point suspension mounting for the cylinder I9. 7

In the cylinder I0 is mounted the pressure operated piston I5 and this piston has the customary piston rod I6 which projects through the rear end or head I4 of the cylinder and carrying thereon exterior to the cylinder the hollow sleevelike operating head I'I. This operating head I! k is mounted between the lifting links I8 that connect with a roller shaft I9 upon which rollers 29 are mounted, said rollers being free to travel longitudinally of thetrack members I. It is notable'that the links I8 converge forwardly to- V ward their points of connection with the roller 7 ing, as

shaft I9 so that the thrust of the said links toward each other is transmitted directly to the crosshead I1 and shaft I9, leaving the rollers 29 entirely free to take care of the vertical component of the thrust action. In other words, there is no tendency on the part of the thrust component of the links I8 to interfere with the free turning of the rollers 29 and the stress set up in'the shaft I9 is purely shear as compared with prior devices of this type, wherein the lifting links employed are so attached usually outside of the rollers as to produce bending stresses in the shaft means that corresponds with the shaft I9 of the present invention, not to mention, in additionthereto, disadvantageous thrusts against the'ends' of the rollers, all of which difficulties are obviated by the present improvements.

Extending rearwardly from the rear end of the cylinder I9 is a combination guide and stop member comprising the guidebar 2 I having its rear end fastened in some substantial manner, as by weldshown at 2 Id, to; one of the crossbars 6 of the frame or chassis. Atits front end the guide member 2I is fastened to a curved supporting plate 2 lb, transversely arranged relatively to the roller tracks l and welded or otherwise fastened 'at its opposite ends to the inner flanges of said tracks. The arrangement of the guide member 2I is such that it is in a plane in substantial parallelism with the horizontal plane including the roller faces of the tracks A and extends over the crosshead I'! so as to guide the latter back and forth in 7 its movement, and furthermore act with stopping effect in a vertical direction to prevent jumping of the crosshead and its rollers fromsupporting relation in respect to the tracks when the dumping body A is being moved upwardly toward itstilted or dumping position. The end 2Iw of the member 2I acts as a stop to limit the rearward movement of the head IT, in an obvious manner.

Within the cylinder I0 and mounted upon the piston rod I6 at the front side of the piston I5 is a coiled spring 22 which encircles the piston rod. This spring moves rearwardly with the piston I5 and piston rod I6 during the pressure stroke for elevating the dump body A, and the rear end of the spring 22 finally abuts with the head I4 at the rear end 10f the'cylinder Ill and becomes compressed during the final movement of the dump body A in reaching its dumping limit of travel. Since the weight of the dump body is not always sufiicient to start the body back to its original or lowered normal position when the cylinder presating function upon relief of said pressure such as will tend to force the piston I5 forwardly as soon as the lifting pressure is .released.

By reason of the three-point suspension or mounting of the cylinder assembly described, it is evident that strains will not be set up in the cylinder assembly by reason of any weaving or distortion of the truck frame in the practical use of the device of the invention.

The movement of the piston I5 in the cylinder is compelled by the admission of fluid at high pressure into the front end of the cylinder through the high pressure line 9; The fluid under pressure acts upon the front side of the piston I5 and forces the same rearwardly, communicating similar movement to the piston rod I6, to the operating head I1, and to rollers 29; also to the'links I 8. During this rearward move ment of the piston I5 the oil or pressure fluid at the rear side of the piston I5 in the cylinder I0 is caused to pass from the cylinder through the low pressure line 24, being admitted to the latter through the low pressure port 23 located near the rear end of the cylinder Ill. When the piston I5 reaches a point in its rearward movement such that it substantially covers entirely the low pressure port 23, there is accomplished substantially a cutting off of the exhaust of the pressure fluid through the low pressure line or pipe 24, and a stopping of the upward travel of the dumping body A as it reaches its final dumping position is accomplished in this way. At this time the spring 22 is compressed fully between the piston I5 and the rear end of the cylinder III. There is provided, see Figure 3, near the rear end of the cylinder II] an oil groove or passage 26, preferably in the bottom wall of the cylinder I0 and leading a short distance rearwardly from the low pressure port 23 toward the rear end of the cylinder. Thus when the high pressure of the fluid in the high pressure pipe or line 9 leading to the front end of the cylinder is released, the inertia and/or weight of the dumping body A and the spring 22 will tend.- to force the piston I5 toward the front end of the cylinder, and this action is facilitated, for the purpose of lowering the dumping body A, by the provision of an oil or fluid passage 26, which, under such conditions, permits'a small quantity of the oil, now: required. to be. carried through entrance of the oil from the low pressure line 24 and port 23 and the passage 26. When, however, the forward movement of the piston I5 has caused the same to clear the port 23 previously covered thereby, the back-flow of the oil through the low pressure line 24 and port 23 will increase in velocity and thereafter the downward movement of the body will be continued at an increased speed. The provision of the groove or passage 26 prevents a looking or the body in its upward or final dumping position, therefore, due to the complete closing of the low pressure port by the piston l5.

In connection with the foregoing it is to be borne in mind that movement of the piston l5 rearwardly in the cylinder I under the action of the high pressure fluid entering through the line 9 requires exit or exhaust of the pressure fluid or oil from the rear side of the piston through the low pressure line 24. Likewise when the high pressure of the fluid in the line 9 is released and the piston I is required to move forwardly in the cylinder H] for lowering of the dumping body, the oil at the front side of the piston I5 is circulated so that it passes out of the cylinder l0 through the high pressure line 9 and re-enters the cylinder 10 at the near side of the piston l5 through the low pressure line 24 and port 23, and at the preliminary stage of the body lowering operation through the passage or groove 26.

For the control of the passage of the fluid pressure medium to the cylinder ID at opposite sides of the piston, l5 there will be utilized the customary provisions associated with the pump 1, these being immaterial to the invention, however.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is

1. In a dumping vehicle of the class described, the combination of a dumping body, a chassis supporting said body, means for raising and lowering the body, including link members connected at one end to the body with an operating head movable longitudinally of the chassis and con-' nected with the other ends of the said link memhere, means for actuating said operating head to move the same in one direction for causing tilting dumping movement of the body and movement in the opposite direction to restore the body to its loading position after dumping, a stop and guide device cooperating with the operating head comprising a guide member extending over the operating head in a direction parallel with the direction of movement of the latter, and intermediate the link members, to prevent upward movement of the head while permitting movement thereof lengthwise of the chassis, one end of said guide member being extended downwardly for engagement with the operating head to limit its movement in one direction, a crossbar in the chassis to which said downwardly extending portion of the guide member is attached, spaced members on the chassis parallel with the said guide members, and a supporting plate disposed transversely of saidspaced members and secured thereto and to the end of the guide member opposite that extended downwardly as above described.

2. In a. dumping vehicle, in combination, a dumping body, a, chassis on which said body is supported, spaced link members connected with the bod; at one end, track members on the chassis in spaced relation, an operating crosshead connected with the other ends of the spaced link members, rollers carried by said crosshead and movable on said track members, actuating means for shifting the crosshead longitudinally of the track members whilst the rollers thereon travel on the latter, said chassis including a. crosspiece or member, and a guide and stop member comprising a guide member disposed above the crosshead to cooperate therewith to hold. the crosshead with its; rollers down on the track members said guide and stop member being disposed intermediate the rollers on the crosshead, said guide member being extended at one end downwardly and connected with said crosspiece of the chassis to form a stop for the crosshead', and a transverse supporting member at the other end of the guide member spanning the space between the track members and attached thereto and cooperating to hold the guide and stop member in proper position relative to the crosshead.

3. In a dumping vehicle of the class described, the combination of a dump body, a chassis upon which the dump body is carried, laterally spaced lifting links connected with the dump body for raising and lowering the same and arranged so as to converge forwardly from their connection with the dump body, thereby disposing the forward ends of the links closer together than at the ends which are connected to the dump body, tracks on said chassis, a cross-head connected to said links, rollers on the ends of the crosshead adapted to move on said track, a cylinder having a piston connected to said cross-head and adapted to reciprocate the same, and a stop member disposed intermediate the rollers on the crosshead adapted to prevent vertical movement of the rollers Without interfering with their reciprocating movement.

PERRY A. BRICK. 

